The present invention relates generally to a device and method of installing sliders on reclosable fasteners of the type used on plastic bags.
Plastic bags for storage of food and other products typically include a reclosable fastener on the mouth of the bag. One form of these bags includes a slider mounted on the reclosable fastener for opening and closing the fastener. Reclosable fasteners with a slider can be assembled separately from a bag or assembled on a bag. In either situation, the fastener is intermittently fed to a machine that stops the fastener to apply preseals at intervals in the fastener. The fastener is then fed or moved down line to locate each preseal adjacent to a notch cutting tool. The fastener is then stopped and a notch is cut in the fastener at the preseal by the cutting tool. The fastener is moved again to position the notch adjacent a slider installation mechanism. The fastener is stopped and a slider is positioned in the notch. The fastener is then restarted while the slider is briefly held in position. This movement of the fastener relative to the slider threads the slider onto the tracks of the fastener. The slider is then released and the fastener and slider are moved to storage, installation on a film or a bag, or if already on a bag, to a cutting station which forms individual bags with associated fasteners with sliders.
This procedure of installing a slider on a fastener requires several stations with each station having a separate, single function tool. Multiple tools at multiple locations is expensive. In addition, intermittent operation slows down the installation of sliders. Correct registration of the fastener and tool is also difficult. A less expensive and faster installation procedure would reduce costs and increase efficiencies.
The present invention is directed to a new device and method for installing sliders onto reclosable fasteners of the type applied to plastic bags. The device includes a rotor with one or more slider pockets for carrying a slider to a notch formed in a reclosable fastener. The rotor also includes one or more cutting tools which are part of the slider pockets or can be separate from the slider pockets.
To install sliders on a reclosable fastener, the fastener is drawn through a presealer that preseals the fastener at intervals. The fastener is then drawn to a position with a presealed area adjacent to the rotor. The rotor is actuated to engage a cutting tool with the fastener to cut out the presealed area. A slider pocket with a slider is then moved adjacent to the cut out presealed area and the fastener is then drawn down line to thread the slider onto the tracks of the fastener.
The device and method of this invention combines several of the devices of the prior art into one device. This reduces cost and the number of times the fastener must be stopped during the slider installation operation thus increasing the speed of the operation and reducing the likelihood of incorrect registration of the fastener with the tools.